ESE's works engine tuner

[wobbly]

If you press a thin sleeve into the stud hole the B port can be ground all the way up to the insert, then widen and hook the port.
The Aux rear wall has plenty of room to get a radial exit with a pocket to turn the flow.
You need to get some parallel header at the exit from the cylinder, and construct a smooth bend into the diffuser,this is worth
1 -2 Hp for free.

[Lucas M]

Ok Wobbly, I will do it like this at the new one. I read somewhere it´s good for flow to make the header straight and this was my solution. So it´s better to make the very first part of the header straight, I understand.
I also did some moldings of every port. Never did this in this cylinder. The result is not bad, but it can be better. What I will do is, get better backflow on the exhaust side of the A-port.
The flow directions of the B-ports doesn´t look bad.
In the exhaust duct, there is some work to do. The port for the aux ports is way too small, like you said. I will do this here with a sleeve in the studs. I think the most power I can gain is with the exhaust pipe and port. Also good to see, the too big volume inside the exhaust duct.

[Muciek]

Using 1 ring piston it's possible to get there a boostport , that could help too. Nice to see that power with such a "simple" cylinder . Here people do 2kg's of welding for cylinder & cases and get probably nowhere near half the potential of engine capacity

[Flettner]

So, Ok, off topic for a moment. LPG what do "we" know about running this as a fuel though a twostroke? Has anyone out there had any experience with this fuel? I'm assuming it would have to be run though an EFI system?

[Mental Trousers]

NOTE post #16193 now has an attachment that Frits asked me to add a week ago.

http://www.kiwibiker.co.nz/forums/sh...post1130813132

[pete376403]

So, Ok, off topic for a moment. LPG what do "we" know about running this as a fuel though a twostroke? Has anyone out there had any experience with this fuel? I'm assuming it would have to be run though an EFI system?

TukTuks that i rode in (as a passenger) in Bangkok were biggish two strokes running LPG. So you now have good cause for a fact finding tour of Thailand. You're welcome.

[speedpro]

All I know is my hiace with 173 holden engine made 2hp more on lpg. If I remember it had some sort of CV device to meter the gas. They run all sorts of stationary engines on gas. The ESE guys should be a help here.

[husaberg]

All I know is my hiace with 173 holden engine made 2hp more on lpg. If I remember it had some sort of CV device to meter the gas. They run all sorts of stationary engines on gas. The ESE guys should be a help here.

Its higher octane than petrol they run a gas regulator, some high power turbo diesels run it now as a intercooling power booster......

[speedpro]

Probably has good latent heat of evaporation seeing as it starts as liquid then vaporises. The mixer was heated by engine cooling system water. Actually it's that exact property that is the mechanism behind LPG powered fridges.

I can just see Flettner's bike with a bbq gas cylinder strapped to the back.

We should talk Rob into using LPG as a coolant. He could route the feed pipe between the fins of the engine. All he'd need was a little pilot light so there wasn't a buildup of flammable gas. It could be fed into some sort of burner tube, possibly with reed valves at the front

[ken seeber]

Orbital was involved in the programme with Bajaj to run the Tuk Tuks on LPG. This was manifold injected in a gaseous state. In conjunction with this was an electronic oil pump that delivered oil based on rpm and load. However in the land of Oz, Ford have a production Falcon that can be supplied with LPG, but manifold injected rather than via a mixer at the start of the inlet manifold. This is called "EcoLPi (Liquid Phase Injection) is a new technology developed by Ford engineers right here in Australia", to use their words. I'd be pretty sure that it is available in NZ as well. Easy to search on, but the guts of it is that it injects liquid LPG rather than gas. However, as a liquid it vaporizes and (due to the latent heat of vaporization) it cools the ingoing air and increases the charge density and increases power over the petrol equivalent.
So for a 2 stroke, it could be neat to inject it to the underside of the piston crown, via a ported piston, eg for the C passage.

Neil, have you worked out how to cast the vanes into the transfer passages? Dunno why I ask, you've probably done it already.

Frits, question on the lower edge of the transfer port being at BDC to cool the piston. If the passage was angled upwards at, say the 25 degs, how much of the ingoing charge would actually sweep across the piston crown, particularly so with crowns that are seemingly becoming flat? Maybe a CFD study might show, by the Coanda effect, that it does, but I'd be a bit surprised. I would have thought that it might be beneficial to have the port floor a little higher to have an ingoing charge enter the cylinder undisturbed by the piston edge, particularly towards BDC when the maximum mass flow is approximately occurring. However I do concede that there are a lot of factors at play that need to be considered, especially the STA.

[Frits Overmars]

LPG probably has good latent heat of evaporation seeing as it starts as liquid then vaporises. The mixer was heated by engine cooling system water.

It is not the mixer that is heated by engine coolant, but the converter that turns high-pressure liquid into low-pressure gaseous LPG.
There are liquid-LPG injection systems on the market now but I always used a second-hand converter. I've ran my cars on LPG all my life as it costs one third the price of petrol and the consumption is only about 10% higher. And you need not worry about a power loss either; you only loose some boot space because of the extra tank.
I've always regulated the engine coolant flow through the converter so that the heat supply is barely enough to vaporize the LPG, which then comes into the inlet manifold as a very cold gas: a gaseous intercooler! That definitely gives more power than petrol.
Once I had a setup that really made the car fly. Until I had to stop at a traffic light. The idling engine circulated less coolant, the converter froze and I had to wait 20 minutes before I could get going again. Not nice on a main crossing.

[Frits Overmars]

NOTE post #16193 now has an attachment that Frits asked me to add a week ago. http://www.kiwibiker.co.nz/forums/sh...post1130813132

Much obliged Shane. Now if you could change the name of the zipfile from fritz.zip to frits.zip, I'd ask you to marry me.

[husaberg]

Much obliged Shane. Now if you could change the name of the zipfile from fritz.zip into frits.zip, I'd ask you to marry me.

Be careful he might say yes........

[Frits Overmars]

Ford have a production Falcon that can be supplied with LPG, but manifold injected rather than via a mixer at the start of the inlet manifold. This is called "EcoLPi (Liquid Phase Injection) is a new technology developed by Ford engineers right here in Australia", to use their words.

I never knew Australia was a part of Holland; liquid LPG injection was developed by the dutch company Vialle over 20 years ago (or maybe 30 years; I'm not sure).

Frits, question on the lower edge of the transfer port being at BDC to cool the piston. If the passage was angled upwards at, say the 25 degs, how much of the ingoing charge would actually sweep across the piston crown, particularly so with crowns that are seemingly becoming flat? Maybe a CFD study might show, by the Coanda effect, that it does, but I'd be a bit surprised.

Jan Thiel found that the 25° axial transfer angle worked best in combination with a spherical piston crown; a flat piston is too much of a stumbling block (literally) for the Coanda effect.
It's hard to say how much of the positive effect came from scavenging, and how much from piston cooling. In any case it begs for more research into radiused piston edges.

I would have thought that it might be beneficial to have the port floor a little higher to have an ingoing charge enter the cylinder undisturbed by the piston edge...

You may well be right, and that should be an extra stimulus for testing curved vanes in the uppermost part of the transfer ducts.

[seattle smitty]

Re LPG in a daily-driver, Frits do you ever have cold start-up problems in mid-winter, before there's any heat around the regulator? I once owned a propane-powered Twin Coach bus that had this issue.

(Still entertaining faint hopes you will comment on my notions, if they are not utterly unworthy of comment, in post 16109, page 1074 . . .)